Cognitive Shadow is term used by Brandon to refer to a spirit that has not yet moved into the afterlife.[2] While the manifestations of this kind of entity can vary depending on the world it occurs on, Cognitive Shadows can occur on any planet of the Cosmere. In general, they are similar to the concept of ghosts on Earth.

Cognitive shadows can be created by a variety of processes. Some of them are created when a person has sufficient attachment to something in the Physical Realm. When a Vessel that has held onto a Shard for a long time dies it becomes a cognitive shadow that can continue to act. [3] The cognitive aspect of a recently deceased person can become a cognitive shadow by finding a source of Investiture to anchor themselves to the Cognitive Realm before passing on to the Beyond. The investiture replaces the parts of the soul that connects it to the Three Realms, providing an anchor for it in the cognitive realm. [4] Some Vessels can prepare a Cognitive shadow at or just prior to their death or Splintering, allowing a portion of their power to continue to function with a small amount of direction, the Stormfather is an example of this.[5]

After his death, Kelsier managed to become a cognitive shadow by investing himself using Preservation's shard pool. After becoming a cognitive shadow he managed to influence the Physical Realm for some time, even holding the Shard Preservation for a time.

Kelsier became a cognitive shadow not through his attachment to the Physical Realm, but by anchoring his mind (his cognitive aspect) to Shadesmar (the Cognitive Realm) with investiture from Preservation's Perpendicularity, the Well of Ascension.

Common on Threnody, Shades are somewhat unique in that they can convert living people into more Shades. This is explained by the kind of Investiture the people on that planet have, as well as the lack of Shard.[9]

A cognitive shadow of Honor on Roshar.[10] Before Honor was killed he began changing the Stormfather making him more intelligent and giving him greater tasks beyond what he could ever have grown to without Honor's tampering.[11]